Expression of an N-terminally truncated form of human focal adhesion kinase in brain.

We have cloned a novel tyrosine kinase that is widely expressed in human tissues using degenerate oligonucleotide primers. The cDNA clone was subsequently found to be the human homologue of the recently cloned chicken focal adhesion associated kinase (pp125FAK). The homology between the chicken and human sequences is 95% at the amino acid level. By RT-PCR we have detected hFAK in human tonsillar T and B cells, several human lymphoid cell lines, a neuroblastoma cell line and HeLa cells. By Northern blot analysis we show that hFAK is expressed in all organs tested with the highest abundance in brain and the least in heart and skeletal muscle. An additional transcript of ca. 3.3 kb, encoding an N-terminally truncated form of hFAK, was observed only in brain.